Wide-area digital transmission facility used predominantly in Europe that carries data at a rate of 2.048 Mbit/s.

E3
Wide-area digital transmission facility used predominantly in Europe that carries data at a rate of 34.368 Mbit/s.

Earth Station
The term used to describe the combination or antenna, low-noise amplifier (LNA), down-converter, and receiver electronics. used to receive a signal transmitted by a satellite. Earth Station antennas vary in size from the.2 foot to 12 foot (65 centimeters to 3.7 meters) diameter size used for TV reception to as large as 100 feet (30 meters) in diameter sometimes used for international communications. The typical antenna used for INTELSAT communication is today 13 to 18 meters or 40 to 60 feet.

Echo Canceller
An electronic circuit which attenuates or eliminates the echo effect on satellite telephony links. Echo cancellers are largely replacing obsolete echo suppressors.

Echo Effect
A time-delayed electronic reflection of a speaker's voice. This is largely eliminated by modern digital echo cancellers.

Eclipse
When a satellite passes through the line between the earth and the sun or the earth and the moon.

Eclipse Protected
Refers to a transponder that can remain powered during the period of an eclipse.

El/Az
An antenna mount providing independent adjustments in elevation and azimuth.

Edge of Coverage
Limit of a satellite's defined service area. In many cases, the EOC is defined as being 3 dB down from the signal level at beam center. However, reception may still be possible beyond the -3dB point.

EIRP
Effective Isotropic Radiated Power - This term describes the strength of the signal leaving the satellite antenna or the transmitting earth station antenna, and is used in determining the C/N and S/N. The transmit power value in units of dBW is expressed by the product of the transponder output power and the gain of the satellite transmit antenna.

Elevation
The upward tilt to a satellite antenna measured in degrees required to aim the antenna at the communications satellite. When. aimed at the horizon, the elevation angle is zero. If it were tilted to a point directly overhead, the satellite antenna would have an elevation of 90 degrees.

Encoder
A device used to electronically alter a signal so that it can only be viewed on a receiver equipped with a special decoder.

Energy Dispersal
A low-frequency waveform combined with the baseband signal prior to modulation, to spread the FM signal's peak power across the available transponder bandwidth in order to reduce the potential for creating interference to ground-based communications services.

EOL
End of Life of a satellite.

Equatorial Orbit
An orbit with a plane parallel to the earth's equator.

ESC
Engineering Service Circuit - The 300-3,400 Hertz voice plus teletype (S+DX) channel used for earth station-to-earth station and earth station-to-operations center communications for the purpose of system maintenance, coordination and general system information dissemination. In analog (FDM/FM) systems there are two S+DX channels available for this purpose in the 4,000-12,000 Hertz portion of the baseband. In digital systems there are one or two channels available which are usually convened to a 32 or 64 Kbps digital signal and combined with the earth station traffic digital bit stream. Modern ESC equipment interfaces with any mix of analog and digital satellite carriers, as well as backhaul terrestrial links to the local switching center.

Eutelsat
The European Telecommunications Satellite Organization which is headquartered in Paris, France. It provides a satellite network for Europe and parts of North Africa and the Middle East.